U.S. Pat. No. 5,147,265 to Pauls et al. discloses two embodiments of an exercise resistance mechanism having many positive attributes. One of these embodiments is shown herein at 30 in FIGS. 1-2, and the other of these embodiments is shown herein at 150 in FIGS. 3-5. For ease of reference, all of the reference numerals in FIGS. 1-5 correspond with those in U.S. Pat. No. 5,147,265. These Prior Art embodiments include a pair of recoil spring packs, one of which is shown in greater detail in FIGS. 6-7, and a pair of reels, one of which is shown in greater detail in FIGS. 8-10.
The basic construction and operation of these Prior Art resistance mechanisms will be described with reference to the embodiment 150 shown in FIGS. 3-5. As shown in FIG. 3, a first flexible line 154 extends from the resistance mechanism housing 151 to a remote end connected to a first operable exercise member (not shown), and a second flexible line 155 extends from the resistance mechanism housing 151 to a remote end connected to a second operable exercise member 196. An opposite end of each flexible line 154, 155 is connected to a respective reel 174, 180 within the resistance mechanism housing 151.
Reel 180, which is representative of reel 174, is shown in greater detail in FIGS. 8-10. Each reel includes a one-way clutch assembly 181 mounted within a reel hub 182. The one-way clutch assembly 181 mounts the reel to a shaft 160 in such a manner that the reel rotates in a first direction together with the shaft (indicated by arrows in FIGS. 4 and 10), and the reel rotates in a second, opposite direction relative to the shaft. The only meaningful distinction between the reel 180 and the reel 174 involves the orientation of the one-way clutch assemblies relative to the shaft. In particular, the clutch assemblies must be oriented to lock in the same direction of rotation and free-wheel in the same direction of rotation when the reels 174 and 180 are mounted on the shaft 160 to face away from one another.
A pair of sidewalls 183a and 183b extend radially away from the hub 182 to define a groove 184 therebetween for receiving several substantially concentric windings of flexible line. A hole 185 is formed through a flanged portion of the hub 182 intermediate the sidewalls 183a and 183b for purposes of retaining an end of the flexible line 155. During assembly of the resistance mechanism 150, the remote end of the line 155 is threaded through the hole 185, and substantially the entire length of the line 155 is pulled through the hole 185. As shown in FIG. 11, an anchor 199 is secured to the opposite end of the line 155 to prevent the opposite end of the line from pulling through the hole 185. Alternatively, the opposite end of the line can be threaded through the hole 185, and the anchor member secured to the opposite end, or a knot formed in the opposite end, as shown in FIG. 1. The slack in the line is then wound onto the reel 180.
As shown in FIGS. 8-9, the hub 182 extends axially beyond one of the sidewalls 183a, and a pair of circumferentially oriented notches 187a and 187b are formed on the axially extending portion of the hub. One of the notches on each reel engages a spring end 164C extending from a respective recoil spring pack 163, one of which is shown in greater detail in FIGS. 6-7. The recoil spring pack 163 includes a cylindrical shell housing 164A having a central aperture 164B. A torsion spring 164 is concentrically wound within the housing 164A, and a hooked end 164C of the spring 164 extends into the central aperture 164B. The recoil spring pack is secured relative to the resistance mechanism housing 151 by means of screws that pass through holes in outwardly extending flanges on the recoil spring pack and through corresponding holes in inwardly extending flanges on resistance mechanism housing 151.
The reel 180 is positioned adjacent the recoil spring pack 163 in such a manner that the axially extending portion of the hub 182 projects into the central aperture 164B. The hooked end 164c of the spring 164 engages the notch 187b to connect the recoil spring pack 163 to the reel 180 in such a manner that rotation of the reel in a first direction relative to the recoil spring pack stores energy in the spring (see arrow in FIG. 10), and rotation of the reel in a second, opposite direction relative to the recoil spring pack releases energy from the spring. The only meaningful distinction between the upper and lower spring recoil packs involves the windings of the spring relative to the shaft. In particular, the springs must wind in the same direction of rotation and unwind in the same direction of rotation when the spring recoil packs are mounted on the shaft 160 to face away from one another. As shown in FIG. 6, the upper spring is wound in the opposite direction as the lower spring, and thus, the hooked end of the upper spring engages the notch 187a on the upper reel.
As shown in FIGS. 4-5, a rotor 166 is connected to the shaft 160 in such a manner that the rotor rotates together with the shaft. Two diametrically opposed brake shoes 167 and 168 are pivotally mounted to opposite ends of the rotor 166 in such a manner that rotation of the shaft 160 causes the brake shoes 167 and 168 to pivot outward, thereby forcing brake pads 170 against a cylindrical contact surface 153 within the resistance mechanism housing 151.
One problem with the Prior Art resistance mechanisms 30 and 150 involves an assembly step in which the reel is connected to a corresponding recoil spring pack. After the recoil spring pack 163 has been secured within the compartment or pocket 161 of the resistance mechanism housing 151, the end 164C of the spring 164 must be connected to the notch 187b. Since the reel 180 obstructs the assembly person's view of the spring end 164C, the connection to the reel must be made by feel without the aid of sight, thereby introducing elements of difficulty and danger into the assembly process. Thus, a need exists to simplify or eliminate this step in the assembly process of this type of exercise resistance mechanism.
Another problem with the Prior Art resistance mechanisms 30 and 150 involves replacement of the flexible line connected to one or both of the reels. The existing line must be removed from the hole 185 in the reel 180 before a new line can be threaded through the hole. However, when the existing line is unwound from the reel to gain access to the end of the existing line, the rewind spring is wound up for purposes of rewinding the reel. At this stage, the reel rotates out of control if the existing line is simply cut, and when the reel stops rotating, no energy is left in the recoil spring for purposes of winding the new line onto the reel. Thus, a need exists to simplify replacement of a flexible line on this type of exercise resistance mechanism.